Relief valve

ABSTRACT

An improved pressure relief valve for tubeless tires or the like is provided. The pressure relief valve includes a novel poppet valve dust cover structure which will automatically reposition the dust cover after each opening or cycle of the relief valve and which will allow the dust cover to act as a secondary poppet valve surface during venting of the pressurized container in which the valve is mounted to increase the rate of fluid flow through the valve. The valve is designed to be sealingly mounted in an aperture in a wall of the pressurized container and may be mounted therein by means of a threaded connection, a clamp connection, a snap-in connection from the interior of the container or a push-in connection from the exterior of the container. The dust cover is attached to the main poppet valve member for axial movement therewith.

This is a continuation of application Ser. No. 610,796, filed Sept. 5,1975, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to pressure relief valves and more particularlyrelates to pressure relief valves for tubeless tires or the like havingdust covers.

DESCRIPTION OF THE PRIOR ART

Pressure relief valves for venting pressurized containers, such astubeless tires, to control the maximum pressure therein are well knownin the prior art. Examples of such valves may be seen by reference toU.S. Pat. Nos. 1,772,107; 2,587,973 and 3,454,033.

The earlier prior art pressure relief valves were not totallysatisfactory as they tended to close or become only partially open whenpressure within the container approached the predetermined maximumpressure which decreased the rate of fluid flow through the valve thusslowing the venting operation and/or they tended to become cloggedand/or inoperative with mud, moisture and/or dust.

Later prior art pressure relief valves utilized dust covers to preventclogging of the valves with mud and/or dust and also for preventingmoisture from entering the valve. The dust covers utilized were nottotally satisfactory as they were rubber flaps which tended to be easilydislodged and required manual resetting and/or were plugs that wereblown off the valve when the valve was open.

The prior art valves were also less than totally satisfactory as theywere mounted in an aperture in a wall of the container, such as anaperture in a tubeless tire rim, by means of threaded clamping or beingsnapped-in from the interior of the container. Such prior art mountingmethods may be drawbacks as they may be time consuming and expensive.

SUMMARY OF THE INVENTION

In accordance with the present invention many of the drawbacks of theprior art have been overcome by the provision of a pressure relief valvewhich includes a dust cover automatically repositioned after each reliefcycle and which acts as a secondary poppet valve surface when the valveis open to maintain the valve open for more rapid venting of an overpressurized container. The valve may be conventionally sealingly mountedin an aperture in the wall of the container or may be pushed in from theexterior of the container.

The above is accomplished by providing a pressure relief valve having avalve body for being sealingly mounted in an aperture in the wall of apressurized container. The valve body has a generally axially extendingpassage therethrough. Fluid flow through the valve is controlled by aspring biased, normally closed, axially movable poppet valve which willallow fluid to flow through the passage and out of the container whenthe fluid pressure acting on poppet valve overcomes the spring bias. Adust cover, or dust seal, covers the exterior opening to the passage.The dust cover is relatively rigidly connected to the poppet valve foraxial movement therewith and fluid flowing through the passage and outof the exterior opening thereto will tend to impinge on the innersurface of the dust cover creating an additional force acting againstthe spring bias to tend to maintain the poppet valve in a full opencondition.

The valve body may include conventional mounting means or may includemeans allowing the body to be sealingly mounted in the aperture byinsertion into the aperture from the exterior of the container.

Accordingly, it is an object of the present invention to provide a newand improved pressure relief valve having an improved dust cover.

Another object of the present invention is to provide a new and improvedpressure relief valve having an improved dust cover which will beautomatically repositioned after each opening of the valve and whichwill tend to retain the valve in the open position when greater thanpredetermined maximum pressure is in the container in which the valve ismounted for more rapid venting thereof.

A further object of the present invention is to provide a new andimproved pressure relief valve having an improved dust cover and animproved valve body allowing the valve to be sealingly mounted in anaperture in the wall of a pressurized container by insertion from theexterior thereof.

These and other objects and advantages of the present invention willbecome apparent from a reading of the detailed description of thepreferred embodiment taken in connection with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view in section of one embodiment of thepresent invention.

FIG. 2 is a front elevational view in section of the pressure reliefvalve of FIG. 1 as mounted in an aperture in a tubeless tire rim or thelike.

FIG. 3 is a front elevational view in section of the valve of FIG. 2 inthe open or venting condition.

FIG. 4 is a front elevational view in section of the valve of thepresent invention in the embodiment of a snap-in valve.

FIG. 5 is a front elevational view in section of the valve of thepresent invention in the embodiment of a clamp-in valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The improved pressure relief valve 10 of the present invention may beseen by reference to the FIGURES. The valve 10 is designed to besealingly mounted in an aperture 14 in the wall 12 of a pressurizedcontainer as is illustrated in FIGS. 2 and 3.

The valve 10 is designed to open and allow pressurized fluid to flow outof the pressurized interior of the container when the pressure in thecontainer exceeds a predetermined maximum. The valve 10 is designed toclose when the interior of the container is at a pressure equal to orless than the predetermined maximum pressure. For purposes ofillustration, the valve 10 will be discussed in terms of an automotivetire pressure relief valve mounted in an aperture in a tubeless tire rimto control the maximum pressure in said tire. It is understood that thepressure relief valve of the present invention is suitable for uses withvarious pressurized containers other than tubeless tires and the like.

The valve 10 comprises a valve body 20 designed to be sealingly mountedin an aperture 14 in the wall or rim 12 of a pressurized container suchas a tubeless tire rim or the like. The valve body 20 is designed formounting from the exterior of the container by forcible insertion of thevalve body 20 into the aperture 14 as will be described in detail below.It is understood that the pressure relief valve of the present inventionmay also be sealingly mounted in an aperture by threaded clamping suchas is seen in U.S. Pat. No. 2,744,559; by being snapped-in from theinterior of the container such as is seen in U.S. Pat. No. 2,818,101 orother commonly used valve mounting techniques. Examples of such snap-inor clamping embodiments are illustrated in FIGS. 4 and 5 respectively.

The valve body 20 illustrated is preferably of rubber or of anequivalent flexible elastic material. A hollow insert 40 is securedwithin the body 20 by known means, such as bonding. The hollow insert ispreferably of a metal, such as steel or brass, which adheres to rubber.The relief valve insides, or core 60, is received within the valveinsert 40.

The valve body comprises a lower end 22 for insertion into the aperture14 in the wall 12 of the pressurized container which is radiallyoutwardly tapered as at 24. The terms upper, lower, top, bottom, etc.,are used for illustrative purposes and refer to the drawings. The termsare not intended to be limiting upon the scope of the present invention.The tapered portion 24 extends upwardly from the leading edge 23 to afirst shoulder 26, which in combination with the enlarged bulbous upperflange 28 defines a groove 30 therebetween. The leading edge 23 of thelower end 22 of the valve body is of a smaller diameter than theaperture 14 while the first shoulder 26 is of a substantially largerdiameter than the aperture 14. The groove 30 includes an axiallyextending, annular bottom wall 32 extending between shoulder 26 andflange 28 which is of a diameter somewhat larger than the diameter ofthe aperture 14 in which the valve 10 is to be sealingly mounted butsomewhat smaller diameter than the outer diameter of shoulder 26 orflange 28. An axially extending annular cavity 34 separates the valvebody 20 from the valve insert 40 axially coincident with the groove 30and the shoulder 26 allowing the valve body to be radially inwardlydeformed for mounting purposes. Axial stretching of the shoulder 26during the installation also results in a smaller diameter of theshoulder making the shoulder easier to force into the aperture.

As may be seen from FIGS. 1 and 2, when the valve body 20 is forciblyinserted, leading edge 23 of lower end 22 first, into the aperture 14,the sides of the wall defining the aperture will engage the taperedportion 24 and then the first shoulder 26, causing the valve body toinwardly deform into cavity 34 as the tapered portion 24 and then theshoulder 26 pass through the aperture 14 until the walls defining theaperture 14 are snapped-into the groove 30. The valve 10 as sealinglymounted in aperture 14 may be seen by reference to FIG. 2. The bulbulousflange 28 is of such diameter to prevent passage thereof through theaperture and generally radially extending, annular surface 29 willdefine the maximum axial penetration of the valve body 20 into theaperture 14.

The hollow valve insert 40 defines an axially extending passage 42through the valve 10. In the mounted position of the valve 10, thepassage 42 extends from the interior to the exterior of the pressurizedcontainer. The insert may include various exterior configurations suchas V-shaped slot 44 for enhancing the bonding retention between thevalve body and the insert. The passage 42 includes a smaller diameterportion 46 at the lower or interior end thereof and a larger diameterportion 48 at the upper or exterior end thereof which meet at a shoulder50 which defines a valve seat. The passage 42 includes an inlet 52 atthe outer end of the smaller diameter portion 46 and an outlet 54 atouter opening to the larger diameter portion 48.

Slidably received within the larger diameter portion 48 of passage 42 ispoppet valve member 62 which carries a seal member 64 for sealingengagement with the valve seat 50 to block fluid flow through thepassage 42. The poppet valve member 62 is the form of a generallycylindrical member which is of smaller diameter than the larger diameterportion 48 of passage 42 allowing fluid to flow around the poppet member62 and out of the outlet 54 when the seal 64 is not in sealing contactwith the valve seat 50.

Located in and axially fixed to the passage 42 adjacent the outlet 54 isa hollow, washer type member 70 which acts as a spring seat for the coilspring 72 which acts on the upper end of poppet valve member 62 to biasthe poppet valve member towards the valve seat 50. Spring seat 70 could,of course, be threadably engaged to the insert 40 for selectivelyadjusting the biasing force applied by spring 72 to poppet valve member62. The spring constant of compressed spring 72 is selected to supply aforce to the poppet valve member equal to the predetermined maximumpressure in the container acting on the exposed surface of the sealingmember 64.

The above defined poppet valve and valve seat structure is known in theart and other functionally equivalent structures may be substitutedtherefor.

Extending through the opening in the spring seat member 70 is an axiallyextending stem 80 which extends from the poppet 62 to the dirt, dustand/or moisture seal/cover 82. The seal/cover 82 is a generally annulardisc which is of sufficient diameter to cover the opening 54 to thepassage 42. The seal/cover may be of a metal, plastic, rubber or acombination thereof. The material selected should be somewhat deformableto provide a good sealing contact between the seal/cover and the outlet54 to prevent the entry of mud, dirt, dust and/or moisture into therelief valve. The seal/cover 82 is coaxial with and exterior to thelarge diameter portion 48 of passage 42.

The axially extending stem 80 may be of two or more portions, such as 84and 86, to compensate for slight misalignments and the like. The stem 80relatively rigidly axially connects the poppet 62 with the dustseal/cover 82 for joint axial movement. The seal/cover 82 is axiallyspaced from the seal 64 such that the seal/cover 82 will engage theoutlet 54 when the seal 64 engages the valve seat 50. The stem 80 may bepermanently or adjustably mounted to the poppet member 62 and theseal/cover 82 by various known means.

In operation, the relief valve and seal/cover structure of the presentinvention provides two advantages over the known prior art.

The seal/cover is coaxial with passage 42 and outlet 54 and will move inaxial unison with the poppet 64 and will thus automatically berepositioned in sealing contact with the outlet 54 when the poppet valvemember seal 64 engages valve seat 50 closing the pressure relief valve10. The seal/cover will also automatically uncover outlet 54 when thepoppet valve member 62 moves axially away from seat 50 to allow fluidflow through the valve.

When pressure within the pressurized container is sufficient to move thepoppet valve member 62 upward against the force of spring 72 to open thevalve (see FIG. 3), air entering the inlet 52, escaping past the valveseat 50, around the poppet member 62 and out of the outlet 54 will tendto impinge on or act against the lower surface 8 of the seal/cover 82.It is noted that the lower surface 8 of seal/cover 82 will remaingenerally perpendicular to the axis of the poppet valve member 62 byvirtue of the relatively rigid connection between stem 80 and seal/cover82. The force of the escaping pressurized air will create a force on thepoppet member 62 which will be additive with the force of pressurizedfluid on seal 64 to move the poppet against the bias of spring 72. Theadditive force of escaping pressurized air acting on the under surface 8of seal/cover 82 which will tend to retain the valve 10 in the fullyopen condition for rapid venting of the pressurized container.

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure has been made only by way of example and that various changesin the details of construction and combination and arrangement of theparts may be resorted to without departing from the spirit and the scopeof the invention as hereinafter claimed.

I claim:
 1. A pressure relief valve for maintaining the pressure withina pressurized container no greater than a predetermined maximumpressure, said valve comprising:a valve body adapted to be sealinglymounted in an aperture in a wall of said pressurized container, saidvalve body having an axially extending passage therethrough, saidpassage having an inlet for fluid communication with the interior of thepressurized container and an outlet for fluid communication with theexterior of the container, said passage defining a valve seat interposedbetween said inlet and said outlet; an axially movable poppet memberslidably received in said passage interposed between said valve seat andsaid outlet, said poppet member having a surface for sealing contactwith said valve seat to prevent fluid flow through said passage; meansfor biasing said poppet member toward said valve seat; a valve stemextending from said poppet member towards said outlet, said stemattached to said poppet member for axial movement therewith; and a covermember exterior of said valve body and attached to said valve stemcausing said cover member to move axially therewith and preventingrelative axial movement therebetween, said cover member beingsufficiently large to cover said outlet, said cover member being axiallyspaced from said poppet member such that said cover member will contactsaid outlet when the poppet member surface sealingly contacts said valveseat, said cover being formed of resilient material such that said covermember is axially flexible in the regions adjacent the outer peripherythereof.
 2. The pressure relief valve of claim 1 wherein said covermember includes a cover surface for engagement with said outlet, saidcover member being generally rigidly mounted to said stem to maintainsaid cover surface generally perpendicular to the axis of said passage.3. The valve of claim 2 wherein said cover member is a substantiallydisc shaped device coaxial with and exterior to said passage.
 4. Thedevice of claim 2 wherein said stem is a multiple piece structure. 5.The device of claim 2 wherein said passage comprises a larger diameterportion adjacent said outlet and a smaller diameter portion adjacentsaid inlet, said valve seat defined by the intersection of said largerand smaller diameter portions.
 6. The valve of claim 5 wherein saidbiasing means is a spring, one end of said spring seated against thepoppet member and the other end of said spring seated against a hollowspring seat fixed in said larger diameter portion adjacent the outlet,said stem passing through said hollow spring seat.
 7. The valve of claim6 wherein said spring seat comprises a washer like member embedded inthe larger diameter portion of said passage.
 8. The valve of claim 6wherein said valve body is adapted to be sealingly mounted in saidaperture by insertion into said aperture from the exterior of saidpressurized container.
 9. The valve of claim 8 wherein said moldedrubber body comprises a leading edge for insertion into the aperture, atapered surface extending radially outwardly from the leading edge to aradially outwardly protruding shoulder and an annular groove definedbetween the shoulder and an enlarged bulbous flange on the end of themolded rubber body opposite the leading edge, said inlet being adjacentthe leading edge and said outlet being adjacent the bulbous flange, saidgroove including an axially extending surface generally parallel to theaxis of the passage and extending from the shoulder to the flange, saidleading edge being of lesser outer diameter than the diameter of saidaperture, said shoulder being of considerably larger outer diameter thanthe diameter of said aperture and said axially extending surface beingof an outer diameter greater than the diameter of the shoulder andsmaller than the outer diameter of the flange.
 10. The valve of claim 9wherein said valve body comprises an axially extending annular cavitybetween said insert and said molded rubber body adjacent said outlet,said cavity extending axially coincident with said shoulder and saidgroove.
 11. The valve of claim 10 wherein said cavity is coaxial withsaid insert, opens to said flange and extends to a point axiallyinterposed between said shoulder and said leading edge.
 12. The valve ofclaim 11 wherein said insert is brass and includes a generally V-shapeddepression on the exterior surface thereof adjacent said inlet.
 13. Thevalve of claim 8 wherein said valve body is a snap-in valve body.
 14. Apressure relief valve comprising a body mountable to a pressurizedcontainer, said body defining an axially extending passage therethroughhaving an inlet in fluid communication with the interior of thecontainer and an outlet, said passage having a valve seat intermediatesaid inlet and said outlet, a poppet slidably mounted in said passage,said poppet having a surface biased to normally contact said valve seatto block the flow of fluid through said passage, and a cover memberexterior of and coaxial with the outlet, said cover member generallyrigidly mounted to said poppet causing said cover member to move axiallytherewith and preventing relative axial movement therebetween, saidcover member axially spaced from the surface of said poppet designed tocontact said valve seat by a distance substantially equal to theseparation of said valve seat and said outlet, said cover being formedof resilient material such that said cover member is axially flexible inthe regions adjacent the outer periphery thereof.
 15. The pressurerelief valve of claim 14 wherein said body comprises an exterior rubberportion and an axially extending hollow insert bonded to said exteriorrubber portion, said passage comprising a larger diameter portionadjacent the outlet and a smaller diameter portion adjacent the inlet,said valve seat defined by the intersection of said larger and smallerdiameter portions, said poppet slidably mounted in said larger diameterportion.
 16. The valve of claim 15 wherein said poppet is biased towardssaid valve seat by a compressed spring extending between said poppet anda generally washer shaped spring seat axially fixed in said largerdiameter portion of said passage adjacent the outlet, said stemextending through the central aperture in said washer shaped springseat.